It's an in-game cinematic using entirely in-game assets for a brief storyline introduced in a minor patch.
Here's just a few of the cutscenes outside of the big high-budget cinematics used to promote the game in the current expansion. As you can see, way more detail. Proper lip syncing. Improved assets.
The amount of effort put into cutscenes is pretty much determined by what the devs feel is needed for a scene and/or how much time they can afford. Also, whether or not your character might appear.
Cutscenes like the one in the OP are my least favorite, for sure. And that scene in particular deserved more work considering the very beginning of that storyline had this cutscene:
The cutscene in the OP is just an easy punching bag.
As far as the character herself, Faerin Lothar? Yeah. Not at all a fan. A black disabled woman (missing an arm) who is always righteous and helps one of the main characters, Anduin Wrynn, overcome his trauma despite him having WAY more life experience than her.
They also made sure to make her a descendant of one of the greatest human characters in the history of WoW, Anduin Lothar. In an ass-pull storyline where a massive fleet of Arathi, THE original human kingdom that splintered into 7 separate states, set sail many years ago, got lost at sea, conquered an entire unknown continent on the other side of the world, and yet everyone just miraculously forgot that happened or didn't know about it.
Though I will say that despite this particular storyline, they've not gone nearly as overboard in The War Within as they did in Dragonflight with the woke shit. Where you met two gay dragonkin who are a couple, two gay centaur who like each other, two lesbians who like each other, a centaur that wants to fuck a dryad (two very different species), and they made the ability for dragons to take on a chosen mortal form as a kind of allegory for transgenderism.